Manhole for steam-boilers.



No. 807,112. PATENTED DEC. 12, 1905. G. T. DAIN.

MANHOLE FOR STEAM BOILERS.

APPLICATION FILED FEB. l, 1906.

UNITED STATES PATENT OFFICE.

- MANHoLE FOR STEAM-BOILERS.

Specification of Letters Patent.

Patented Dec. 12, 1905 Application filed February 1, 1905. Serial No. 243.6%.

T aZZ whom it may concernx Be it known that I, CHARLES T. DAIN, a citizen of the United States, residing at Coatesville, in the county of Chester and State of Pennsylvania, have invented certain new and useful Improvements in Manholes for Steam-Boilers, &c. and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art-to which it appertains to make and use the same.

My invention is directed to the production of a manhole-flange of wedge shape in crosssection, whereby its strength and stiffness is increased and a larger area of j oint-forming edge is provided as a seat for the cover. For this purpose the metal is integrally transferred from the sheet into the flange to thicken its joint-forming edge, flueing the manhole with a flange having athickened j oint-forming edge, and in the claims appended hereto I will point out, in connection with the accompanying drawings, wherein my said invention resides.

Referring to the drawings, Figure 1 is a partial longitudinal section of a steam-boiler, showing my improved manhole flanged bearing for the cover in two forms of its application. Fig. 2 shows, enlarged, the manhole flanged bearing for the cover in the boilerhead. Fig. 3 shows in section the boilerhead, illustrating the first step by corrugating-dies in the method of producing my 1mproved bearing-flange for manhole-covers. Fig. 4 is a like view illustrating the second step by swaging-dies in the method of producing my improved bearing-flange for manhole-covers. Fig. 5 shows a like view, the plunger-die in the position it occupies to form the Wedge-shaped part into the bearingflange. Fig. 6 is a like view illustrating the finishing step by a plunger-die in the method of producing my improved wedge -shaped bearing-flange for manhole-covers. Fig. 7 is a section taken lengthwise of the manhole.

I have shown a portion of a steamboiler having my improved manhole flanged bearing; but such manhole flanged bearing may be formed in tanks where steam-tight joints are necessary. 7 In Fig. 1 I have shown my thickened flan e-bearing as formed integral with the suitable form that will make a steam-tight joint on the flange, and the matter which constitutes my improvement is the flange having an upset thickened bearing edge 5 for the cover-joint, whereby to afford a greater area of joint-forming surface as a seat for the cover and to give greater strength and stiffness to the flange.v This thickened edge is produced in the operation of forming the bearing-flange, which is thereby caused to take the form of a wedge in cross-section, so that one of its walls 6 will stand oblique to the body'from which it is formed and its other wall at right angles to such body. Upon the thickened edge of the manhole-flange the cover is seated and clamped by any suitable fastenings, by which the edge of the cover will form the steam-tight joint, reinforced by a gasket 7 upon the thickened edge of the flange. A yoke or arched bar 8 and a center bolt 9 may form the clamping means.

The feature of the invention resides in the wed e form of the manhole-flange. The metal for that purpose is taken from the sheet and transferred to the flange, and for this purpose I have shown a method or one means by which this transfer of metal is effected; but my invention is not confined to this method. The 0 ening, which may be of the usual elliptical orm, having been formed in the sheet, the edge around the opening is then heated to a soft heat, and, referring to Fig. ,3, the sheet, as in a boiler-head, is' properly supported level upon a fixed die 10, so that said opening will be centered with said die, which for this purpose has a face-guide 1 1 conforming to the form of the opening. At a suitable distance from and surrounding this guide the die is formed witha face-groove 12, corre sponding in contour to the form of the manhole. A plunger-die 13, having a face-bead 14 the counterpart of and registering with the fixed die-groove, is then forced down upon the sheet, pressing the sheet metal into the groove, forming thereby a corrugation in the sheet surrounding the edge of the manhole. The metal thus swaged into this corrugation is to form the thickened edge of the manhole bearing-flange, as shown 111 Fig. 4. For this purpose the sheet is removed from the corrugating-dies and the corrugated part subjected to a welding heat and properly centered and supported level upon a fixed ring part 15, corresponding with the corrugation of the sheet, the latter being seated upon the ring a short distance from the base of the corrugation. A die 16,having an unbroken face, is then forced down upon the corrugated art of the sheet, clamping it firmly upon the ed ring. A die 17, having an inward sloping or dish-like face around a central opening, is then forced u against the corrugation, reducing and flattening it by crowding the metal which forms it into a form correspond ing to the sunken face of the die, the surface of which slopes from its outer edge to its central opening, forming thereby a recess 18, and gives the corrugated part a wedge form terminating at the clamped part of the sheet shown in Fig. 5. The sheet is then transferred to and centered upon a fixed ring-die 19 and properly supported thereon, having the form of the opening formed by the wedgeshaped part of the sheet, the inner Walls 20 of said ring allowing the free bending of the thickened wedge part of the sheet. A plunger-die 21, having an unbroken face, is then forced down upon the thickened part, upsetting it into the bearing-flange for the cover and forming the manhole. This is called the flueing operation.

Referring to'Fig. 4, it is important to note that by reason of the firm clamping function of the die upon the fixed ring the displacement of the metal in the corrugation can only be toward the edge of the opening bounding the corrugation, and therefore the metal in the corrugation can only be driven or crowded toward said opening. Therefore to form a stop to the displacement of the corrugation in this direction the clamping-die is formed with a depending center part 22, which, passing through the opening in the sheet, forms an abutting wall against which the metal is swaged to give it the Wedge form, it being understood that the swagingdie has an opening to receive the depending center part of the clamping-die. It is also important to note the die-face recess is so formed as to cause the edge of the clampingdie to rest upon the sheet at the point at which the latter rests upon the top edge of the fixed ring, so that the sheet is clamped upon said ring outside of the sWaging-die before the latter commences its swaging action. In forming the corrugation the manhole is enlarged, while the displacing the corrugation into the wedge form is effected without lessening the required area of the manhole. The thickened edge of the manhole-flange is faced off perfectly smooth to make a good seat for the rubber gasket.

The bearing manhole flange may be formed either inward or outward of the closure-sheet or formed as a separate saddlering of steel, and when in this form the saddle-plate is seated within an opening in the sheet or shell and is riveted thereto.

I claim 1. The bearing edge of the turned flange of a manhole-cover having its oint-forming edge of greater width in a single thickness than the thickness of the plate from which said bearing edge is projected and terminates in said turned flange.

2. A manhole bearing-flange for the cover said flange upset into a Wedge form of a single thickness to increase the area of its ointforming edge and render the flange stronger.

3. The combination of a metal sheet hav ing a flange upset around a manhole of Wedge form and of a single thickness in cross-section to increase its joint forming area, a cover, and means for clamping the same upon said thickened flange edge.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

CHARLES T. DAIN.

Witnesses E. D. BALDWIN, THOMAS J. GIBSON. 

